This invention relates to a machine tool having a spindle head.
In order to increase machining efficiency, a spindle of a machine tool is designed to operate at a high speed. If the spindle rotates at a high speed for a long time, a lot of heat is produced at bearings, gears and other related members. As a result, the spindle and the spindle head supporting it are apt to deform due to the heat so as to decrease machining precision.